392947921 has 8 divisors (see below), whose sum is σ = 398359080. Its totient is φ = 387573888.

The previous prime is 392947913. The next prime is 392947931. The reversal of 392947921 is 129749293.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 72931600 + 320016321 = 8540^2 + 17889^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 392947921 - 2³ = 392947913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (392947931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12375 + ... + 30643.

It is an arithmetic number, because the mean of its divisors is an integer number (49794885).

Almost surely, 2^392947921 is an apocalyptic number.

It is an amenable number.

392947921 is a deficient number, since it is larger than the sum of its proper divisors (5411159).

392947921 is a wasteful number, since it uses less digits than its factorization.

392947921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18563.

The product of its digits is 244944, while the sum is 46.

The square root of 392947921 is about 19822.9140390610. The cubic root of 392947921 is about 732.4505876658.

The spelling of 392947921 in words is "three hundred ninety-two million, nine hundred forty-seven thousand, nine hundred twenty-one".